On the Forcing of the Radial-vertical Circulation within Cyclones-Part 1: Concepts and Equations

作     者：D.R.Johnson 

作者机构：Space Science and Engineering Center University of Wisconsin-Madison Madison USA 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：1998年第15卷第3期

页      面：64-85页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：National Aeronautics and Space Administration NASA: NAG5-81 

主　　题：The forcing of the radial-vertical circulation Quasi-Lagrangian diagnostics of cyclones,Balanced equation 

摘      要：お? Following the theoretical result of Eliassen, the Sawyer-Eliassen equation for frontal circulations and the equation for forcing the meridional circulation within a circumpolar vortex are extended in isentropic coordinates to describe the forcing of the azimuthally averaged mass-weighted radial-vertical circulation within translating extratropical and tropical cyclones. Several physical processes which are not evident in studies employing isobaric coordinates are isolated in this isentropic study. These processes include the effects of pressure torque, inertial torque and storm translation that are associated with the asymmetric structure in isentropic coordinates. This isentropic study also includes the effects of eddy angular momentum transport, diabatic heating and frictional torque that are common in both isentropic and isobaric studies. All of the processes are modulated by static, inertial and baroclinic stabilities.  Consistent with the theoretical result of Eliassen, the numerical solution from this isentropic study shows that the roles of torque, diabatic heating and hydrodynamic stability in forcing the radial-vertical circulation within stable vortices are that 1) positive (negative) torque which results in the counterclockwise (clockwise) rotation of vortices also forces the outflow (inflow) branch of the radial-vertical circulation, 2) diabatic heating (cooling) forces the ascent (descent) branch of the radial-vertical circulation and 3) for given forcing, the weaker hydrodynamic stability results in a stronger radial-vertical circulation. It is the net inflow or convergence (net outflow or divergence), vertical motions and the associated redistribution of properties that favor the evolution of vortices with colorful weather events.  Numerical solutions of this isentropic study are given in companion articles. The relatively important contribution of various physical processes to the forcing of the azimuthally-averaged mass-weighted radial-